This invention relates to a suspension and seal system for a refrigeration motor compressor unit, and in particular, to such a system particularly suitable for use in hermetically sealed units wherein refrigerant gas at discharge pressure substantially surrounds the motor and compressor of the unit.
It is well recognized that a motor and compressor mounted within a hermetically sealed shell must be resiliently supported to prevent noise transmission from the interior of the shell to the exterior thereof. In addition, the support or suspension system must function to minimize or eliminate extensive movement of the motor and compressor in the shell such as might occur due to torsional forces developed during start-up of the unit. It is essential that excessive movement of the motor and compressor within the shell be prevented to prevent damage to components thereof, such as the motor windings and lubricating oil pump.
It has been found that the energy efficiency of a motor compressor unit can be significantly increased by filling the chamber in which the motor and compressor are mounted with refrigerant gas at discharge pressure. Heretofore, it has been the practice to fill the chamber with gas at suction pressure, with the gas cooling the motor's windings prior to entry into the compressor's cylinders. In the present arrangement, the suction gas is not used for motor cooling, but rather is led to a relatively small chamber in direct flow communication with the compressor cylinder. The temperature of the gas is thus maintained at a minimum prior to compression. To insure minimum heat transfer between the relatively high temperature refrigerant gas contained within the major portion of the shell and the relatively low temperature refrigerant gas contained within the realatively small chamber adjacent the cylinder, it is necessary to provide a seal.
The present invention particularly relates to a suspension system which, not only supports the motor and compressor within a hermetically sealed shell, but in addition, provides a seal for physically separating suction gas from discharge gas and for minimizing heat transfer between the suction and discharge gas.